The topography of Arunachal Pradesh is an undulating hilly terrain. Many big and small tributaries of mighty Brahmaputra flow through the hilly slopes of Arunachal Pradesh. River bank erosion, landslides are inevitable and many gullies are formed here. Hence, cultivable flat land is very limited as compared to its area. In some parts of the state there are marshy lands also. Therefore it is urgently necessary to protect and develop such types of less cultivable land.

Aiming at this, the department executes land development/land reclamation and land protection work to bring more land under agriculture and protection of agricultural land from erosion. Under this programme, most often land is reclaimed in degraded marshy land by drainage works and suitable flat land in hilly areas and valleys are developed for permanent cultivation by land levelling and bunding, Similarly, terraces and graded bunds are made on gentle hill slopes so as to provide permanent cultivable lands to the people, including improvement of age old practices of cultivation. The teracces and bunds are being promoted to wean people away from the practice of jhumming, which because of shortened cycles is now detrimental to the environment.

The Rural Works Department is the nodal agency for soil and water conservation activities in the state. The department has taken up a number of schemes under this sector. The different types of soil conservation works taken up are land development by terracing at hill slopes, bunding on lands with moderate slope, land protection with engineering structures such as wire crated boulder spurs, guide walls, etc., as well as vegetative measures of conservation.

Under the land protection programme, which is of utmost importance because of topographical conditions and heavy rainfall in the state, different types of engineering measures are taken up to protect valuable agricultural land. Over the years, this work has attained maximum importance with the department. To reduce the ill effects of soil erosion, suitable schemes for providing vegetative coverage in the affected areas are also taken up.

The department has a large fleet of machinery including heavy and light vehicles mainly used for construction, maintenance and supervision of roads and soil conservation works which comprises the following:

Type of Machinery

Number

Bulldozer

16

Excavator-loader

4

Road-roller

12

Tractor

87

Truck

22

Gypsy/van/jeep

69

Ambassador

4

The soil survey wing of RWD has been conducting important studies/activities which are reflected below:

(i) The soil survey wing had completed a reconnaissance soil survey of the entire Arunachal Pradesh, district-wise, i.e. an area of 83,743 sq. km.

The soil survey reports of all the districts have been published. These reports contain physiographic/drainage, soil and land capability class maps along with basic information on soils and their potentials and problems and its use and management. Soil survey data is the backbone for any developmental schemes.

(ii) Hydrogeomorphological studies (1989-1991):The soil survey wing of RWD had undertaken exploratory survey in collaboration with National Remote Sensing Agency, Hyderabad, during the period from September 1989 to November 1989 for preparing hydrogeomorphological maps of Arunachal Pradesh district-wise in the scale of 1:250,000 using the remote sensing technique. The maps indicate the geomorphic unit, lithostratigraphic unit, structure, ground water prospects, etc.

(iii) Land use and land cover studies (1989-1991):The soil survey wing of RWD had undertaken exploratory survey in collaboration with Indian Institute of Remote Sensing, Dehradun, during the period from December 1989 to May 1990 for the preparation of land use and land cover maps of Arunachal Pradesh, district-wise, in the scale of 1:250,000 using the remote sensing technique.